Never ran with the exhaust uncorked with the 383 as far as I know. We wanted to keep everything the same just change engines. Of course the intake had to be changed. The 383 had an M1. The 440 has a Torker II. Carb is a Demon 850. Valve springs are Comp 928. 150 closed 371 open. Cam is also a Comp. Solid flat tappet, 252* @.050 with .540I lift. The 383 had dome pistons at 11.2:1 compression. The 440 is .030" over and has flat tops at 10.5:1 compression. Quench is .054". Pistons are .015 in the hole and .039" gasket. I think he should go a little bigger with the cam, maybe to a 259* or 260* and more closer to .600 lift. He does run race gas.